Field of the Invention
The present invention relates generally to fall protection safety devices and, in particular, to a cable grab device for use in connection with a generally vertically-extending cable or line, such as a cable that runs along a ladder or cage on the side of a structure.
Description of Related Art
There are many structures and buildings, e.g., skyscrapers, towers, bridges, cell-phone towers, tall industrial buildings, antenna structures, and the like, that require maintenance or access thereto from the bottom area to the top area. In order to provide access to the various areas or floors of such structures or buildings, a ladder will be constructed and attached to the side of the structure or building. Typically, this ladder will be surrounded by a cage to ensure that maintenance or other persons traversing the ladder will not fall if they lean backward too far and lose their grip. To provide further safety measures, a cable may be positioned adjacent the ladder and within the cage, where the cable extends from the bottom to the top of the ladder. In use, the person will attach a fall protection device (sometimes referred to as a “cable grab”) to the cable, and will connect an attachment member, such as a carabiner, to the device with a line attached between the carabiner and a connection point on the person (e.g., a connection point on a lanyard, belt, harness, and the like). This fall protection device will allow free movement as the person climbs up or down the ladder. However, if the movement in the downward direction is too fast, the fall protection device will operate to grip or contact the cable and brake or stop movement in the downward direction, thereby protecting the person from falling down through the cage.
As is known in the art, and as illustrated in FIGS. 1-7 in various orientations and modes of operation, a known cable grab device 200 includes a first lateral member 202 having a channel 203 configured to receive and retain a cable (C), a second lateral member 204 spaced from the first lateral member 202, a first pivot member 206 pivotally attached between a first end of the first lateral member 202 and a first end of the second lateral member 204, and a second pivot member 208 pivotally attached between a second end of the first lateral member 202 and a second end of the second lateral member 204. An attachment member opening 209 extends through the second lateral member 204, and an attachment member (not shown, e.g., a carabiner or the like) can be removably attached through the attachment member opening 208. With reference to FIG. 6, and when the cable grab device 200 is moved or urged in a generally downward direction, and at a specified point, the first end of the first pivot member 206 and the first end of the second pivot member 208 contacts and/or bears against the cable (C), which brakes or stops the movement of the cable grab device 200 in the downward direction. In this manner, if the maintenance person falls down through the cage, the cable grab device 200 will brake and stop its downward movement, which will arrest the fall of the person via attachment between the cable grab device 200, the attachment member, and the person (or device or arrangement worn by the person).
One drawback with respect to this existing cable grab device 200 is that, due to its proximity to the user, the person's first instinct when falling may be to grab the cable grab device 200. If the person grabs the cable grab device 200 and forces it to close or articulate in the downward direction (as intended), then the cable grab device 200 will still operate effectively, contact the cable (C), and arrest the person's fall (again, as illustrated in FIG. 6). However, and as illustrated in FIG. 7, if the person grabs the cable grab device 200 and forces it to articulate in the upward direction, then the cable grab device 200 cannot contact the cable (C) and cannot arrest the person's fall.
Accordingly, there is a need in the art for an improved cable grab device. There is also a need in the art for a fall protection device that provides a fall arrest operation regardless of how the device is closed or articulated.